SIMULATION

The problems of planning for economic develop ment arise from the interplay of the political, social, and economic subsystems of a developing country. These problems are characterized by the uncer tainty necessarily inherent in any process of plan ning for the future — uncertainty arising both from the quantity and quality of available data and from the difficulties of forecasting how a large-scale system of complex interactive and feedback relation ships will respond to policy inputs. In this paper, generalized system simulation is offered as an ap proach to dealing with these problems. It is a flexi ble, iterative, problem-investigating process that includes problem formulation, mathematical modeling, model testing and refinement, and appli cation of the model to solve problems — all in close consultation with decision-makers. As an illus tration, an overview will be given of a policy- oriented system simulation model of the Nigerian economy. The model consists of two detailed re gional agricultural submodels, an aggregated na tional nonagricultural submodel, and components which model Nigeria's population and the inter- regional trade in food. Finally, I shall outline how the generalized system simulation approach could be implemented within the development-planning and policy-making process.

SIMULATION owes a vote of thanks to many contributors --but chiefly responsible for its continual publica tion of material documenting advances in the state of the art of simulation are five people, four of whom have remained in their original posts with the journal since its first issue: its editor, its pub lisher, its director of publications, its chairman of the editorial board, and its original graphic artist. We reprint on this and the following four pages por tions from their original presentations to readers in the early issues of the journal.

Below--our Editor, John MeLeod, who has borne the major share of the responsibility for producing an issue of professional material month-in month-out over the ten-year period.

Since publication of the first issue, Stan Rogers has served continuously as both Publisher of SIMULATION and Secretary of Simulation Councils. Since his retirement from General Dynamics in 1970, he has assumed several different hats as well, in- cluding that of Editor-in-Chief of the SIMULATION COUNCILS PROCEEDINGS series. Stan's original "Presenting" was updated in the May 1971 issue when he became the fourth recipient of the Electronic Associates Senior Scientific Simula- tion award.

The Director of Publications of a new society launch ing its own publication takes on a large job. It is he who must assume final responsibility for the es tablishment of style, the balancing of the budget, the integrity of the journal, and the supervision of the editorial, publications, and graphics departments.

But Jack's contributions to SIMULATION and SCi have far exceeded the execution of these demanding respon sibilities, They include, among others, his service as Advertising Manager, SCi President, and Represen tative first to AFIPS and then to the JCC Board--all at critical times in SCi's history.

With his service as Chairman of SIMULATION's Editorial Board, his extensive screening of the review process, and his own professional writings, Granino Korn has contributed immeasurably to the journal's high professional standards.

SIMULATION also owes a large debt of gratitude to the other members of the Editorial Board, who were presented in later issues and who are listed below:

Paul J. Hermann Ladis D. Kovach Homer R. Warner Walter J. Karplus Arthur I. Rubin